Application of membrane techniques to produce drinking water in China

Ultrafiltration of Binxian reservoir (near Harbin in China) water to produce drinking water was investigated in this study. Membrane flux declined with temperature coming down. Using coagulation before UF not only increases the permeate flux, but also retards the permeability decline. In comparison to the normal backwashing in which flow is reversed across the membrane once during each backwash cycle, two consecutive backwashing pulses during each cycle is an optimized operation. A chemical cleaning may be required to restore the initial performance of the membrane when the fouling occurs. As for Binxian reservoir water, 0.1% citric acid is a proper cleaning solution. Membrane filtration offers fewer coagulation agents needed and good quality of produced water.